From: Eric Dumazet edumazet@google.com
[ Upstream commit b69dd5b3780a7298bd893816a09da751bc0636f7 ]
Some arches support cmpxchg() on 4-byte and 8-byte only. Increase mr_ifc_count width to 32bit to fix this problem.
Fixes: 4a2b285e7e10 ("net: igmp: fix data-race in igmp_ifc_timer_expire()") Signed-off-by: Eric Dumazet edumazet@google.com Reported-by: Guenter Roeck linux@roeck-us.net Link: https://lore.kernel.org/r/20210811195715.3684218-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/inetdevice.h | 2 +- net/ipv4/igmp.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h index a64f21a97369..131f93f8d587 100644 --- a/include/linux/inetdevice.h +++ b/include/linux/inetdevice.h @@ -41,7 +41,7 @@ struct in_device { unsigned long mr_qri; /* Query Response Interval */ unsigned char mr_qrv; /* Query Robustness Variable */ unsigned char mr_gq_running; - unsigned char mr_ifc_count; + u32 mr_ifc_count; struct timer_list mr_gq_timer; /* general query timer */ struct timer_list mr_ifc_timer; /* interface change timer */
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index 95ec3923083f..dca7fe0ae24a 100644 --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -807,7 +807,7 @@ static void igmp_gq_timer_expire(struct timer_list *t) static void igmp_ifc_timer_expire(struct timer_list *t) { struct in_device *in_dev = from_timer(in_dev, t, mr_ifc_timer); - u8 mr_ifc_count; + u32 mr_ifc_count;
igmpv3_send_cr(in_dev); restart: